Yu Dejian, Cao Fei, Shen Yalong, Liu Xuhai, Zhu Ying, Zeng Haibo
Institute of Optoelectronics & Nanimaterials, MIIT Key Laboratory of Advanced Display Material and Devices, College of Materials Science and Engineering, Nanjing University of Science and Technology , Nanjing 210094, China.
J Phys Chem Lett. 2017 Jun 15;8(12):2565-2572. doi: 10.1021/acs.jpclett.7b00993. Epub 2017 May 25.
Two-dimensional (2D) homologous halide perovskite (HP) microcrystallines have emerged as a promising alternative light-sensitive material; however, the undesirable quantum confinement effect and severe interfacial charge-carrier scattering still hamper their applications in photodetectors (PDs). Here we propose a novel postsynthetic treatment to simultaneously solve both problems. 2D (OA)FAPbBr (OA and FA represent octadecylamine and formamidine) microplatelet film was immersed in solution containing FA, leading to improvements in two aspects. First, the dimensionality of 2D HPs was increased through an exchange reaction between OA and FA, which meliorates the quantum confinement effect and facilitates the separation of electrons and holes; second, the free-standing 2D HP microcrystallines were fused for promoted interdomain charge-carrier transport. The treated PDs achieved a 3600 and 4200% increase in external quantum yield and responsivity up to 7100% and 32 A/W, respectively, and the rise/decay time was shortened by two orders of magnitude to 0.25/1.45 ms.
二维（2D）同系卤化物钙钛矿（HP）微晶已成为一种很有前景的替代光敏材料；然而，不良的量子限制效应和严重的界面电荷载流子散射仍然阻碍了它们在光电探测器（PD）中的应用。在此，我们提出一种新颖的合成后处理方法来同时解决这两个问题。将二维（OA）FAPbBr（OA和FA分别代表十八烷基胺和甲脒）微片膜浸入含有FA的溶液中，在两个方面带来了改善。首先，通过OA与FA之间的交换反应增加了二维HP的维度，这改善了量子限制效应并促进了电子和空穴的分离；其次，独立的二维HP微晶融合在一起，促进了域间电荷载流子传输。经过处理的光电探测器的外量子效率提高了3600%和4200%，响应度分别高达7100%和32 A/W，上升/下降时间缩短了两个数量级，至0.25/1.45 ms。
